feat: Implement Diagnostic Pull for TextDocument

src/CSharpLanguageServer/Handlers/Diagnostic.fs

@@ -1,14 +1,84 @@
 namespace CSharpLanguageServer.Handlers
 
+open System
+
+open Ionide.LanguageServerProtocol.Server
 open Ionide.LanguageServerProtocol.Types
 
+open CSharpLanguageServer.Conversions
 open CSharpLanguageServer.State
+open CSharpLanguageServer.Types
+open CSharpLanguageServer.Logging
 
 [<RequireQualifiedAccess>]
 module Diagnostic =
-    let provider (clientCapabilities: ClientCapabilities) = None
+    let private logger = LogProvider.getLoggerByName "Diagnostic"
+
+    let private dynamicRegistration (clientCapabilities: ClientCapabilities) =
+        clientCapabilities.TextDocument
+        |> Option.bind (fun x -> x.Diagnostic)
+        |> Option.bind (fun x -> x.DynamicRegistration)
+        |> Option.defaultValue false
+
+    let provider (clientCapabilities: ClientCapabilities): U2<DiagnosticOptions, DiagnosticRegistrationOptions> option =
+        match dynamicRegistration clientCapabilities with
+        | true -> None
+        | false ->
+            let diagnosticOptions: DiagnosticRegistrationOptions =
+                { DocumentSelector = Some defaultDocumentSelector
+                  WorkDoneProgress = None
+                  Identifier = None
+                  InterFileDependencies = false
+                  WorkspaceDiagnostics = false
+                  Id = None
+                }
+
+            Some (U2.C2 diagnosticOptions)
+
+    let registration (clientCapabilities: ClientCapabilities) : Registration option =
+        match dynamicRegistration clientCapabilities with
+        | false -> None
+        | true ->
+            let registerOptions: DiagnosticRegistrationOptions =
+                { DocumentSelector = Some defaultDocumentSelector
+                  WorkDoneProgress = None
+                  Identifier = None
+                  InterFileDependencies = false
+                  WorkspaceDiagnostics = false
+                  Id = None }
+
+            Some
+                { Id = Guid.NewGuid().ToString()
+                  Method = "textDocument/diagnostic"
+                  RegisterOptions = registerOptions |> serialize |> Some }
+
+    let handle (context: ServerRequestContext) (p: DocumentDiagnosticParams) : AsyncLspResult<DocumentDiagnosticReport> = async {
+        let emptyReport: RelatedFullDocumentDiagnosticReport =
+            {
+                Kind = "full"
+                ResultId = None
+                Items = [| |]
+                RelatedDocuments = None
+            }
+
+        match context.GetDocument p.TextDocument.Uri with
+        | None ->
+            return emptyReport |> U2.C1 |> LspResult.success
+
+        | Some doc ->
+            let! ct = Async.CancellationToken
+            let! semanticModelMaybe = doc.GetSemanticModelAsync(ct) |> Async.AwaitTask
+            match semanticModelMaybe |> Option.ofObj with
+            | Some semanticModel ->
+                let diagnostics =
+                    semanticModel.GetDiagnostics()
+                    |> Seq.map Diagnostic.fromRoslynDiagnostic
+                    |> Array.ofSeq
 
-    let registration (clientCapabilities: ClientCapabilities) : Registration option = None
+                return { emptyReport with Items = diagnostics }
+                       |> U2.C1
+                       |> LspResult.success
 
-    let handle (context: ServerRequestContext) (def: DocumentDiagnosticParams) : AsyncLspResult<DocumentDiagnosticReport> =
-        LspResult.notImplemented<DocumentDiagnosticReport> |> async.Return
+            | None ->
+                return emptyReport |> U2.C1 |> LspResult.success
+    }